Rename crate from 'xml-rs' to 'xml'

[dtolnay]

Every crate on crates.io is for Rust :smile: no reason for the -rs suffix.

[netvl]

I may rename it when I release the next large version. But still, there are many crates with -rs suffix out there :)

[RReverser]

@netvl I'm surprised Cargo itself didn't strip the suffix for you as it does nowadays for any new project.

[vi]

Now it has stopped doing that.

[kornelski]

The xml crate is owned by @Plecra

[kornelski]

Done! 🎉